| 摘要 |
<p>A laser beam emitted from a semiconductor laser (11) is radiated and scanned on a bundle of paper materials which is being conveyed, and the laser beam reflected by the bundle is received by a plurality of photocells (15, 16, 17, 18) to be converted to electrical signals. A signal synthesizer (30) synthesizes the electrical signals output from the photocells (15, 16, 17, 18). A binary circuit (39) binarizes the synthesized signal to generate a boundary signal corresponding to a boundary between packs included in the bundle. A CPU (42) detects the number of packs included in the bundle on the basis of the number of boundary signals.</p> |
